GB1: Chapter 11 Flashcards
Quorum Sensing
When bacteria senses the concentration of signaling molecules (secreted by another bacterial cell), bacteria monitors its own local cell density
biofilm
aggregation of bacterial cells attached to surface by molecules secreted by cells, but only after cells have reached certain density.
biofilm protects cells in it
local signaling
communication through signaling molecules targeted for cell that may/may not be immediately adjacent
synapse
narrow space between nerve cell and target cell
paracine signaling
signaling over short distances
growth factors
local regulators in animals, compounds that stimulate nearby target cells to grow and divide. many cells all at once can respond to these growth factors produced by one cell
Signal transduction pathway
sequences of changes in series of different molecules
- relay molecules are those involved in pathway
ligand
molecule that specifically binds to another (usually larger) molecule
G protein
protein that binds energy-rich molecule GTP (guanosine triphosphate, similar to ATP)
signal transduction pathway
chain of molecular interactions leading to particular cellular response
second messengers
small, nonprotein, water-soluble molecules or ions
adenylyl cyclase
- enzyme built into plasma membrane
- produces cAMP from ATP by cleaving 2 phosphates from ATP
protein kinase A (activated by concentration of cAMP)
serine/theronine kinase
IP3 & DAG
IP3: inostiol trisphosphate
DAG: diacylglycerol
- 2nd messengers
- Made from cleavage of certain type of phospholipids in plasma membrane
scaffolding proteins
large relay proteins for other proteins in cascade to efficiently transfer signal (they’re closer to each other in proximity)
